Nail driving device



2 Sheets-Sheet 1 P. H. BRENNAN NAIL DRIVING DEVICE INVENTOR.

Jan. 23, 1951 Filed Feb. 15, 1949 Jan. 23, 1 951 P. H. BRENNAN NAILDRIVING DEVICE 2 Sheets-Sheet 2 Filed Feb. 15, 1949 INVENTOR. ZZ /1 61fire/7,741

Patented Jan. 23, [951 I .i

UNITED STATES PATENT Patrick H. Brennan, Detroit, Mich. 7 ApplicationFebruary 15, 1949," ser al No. 741543 employed with a' minimum of skilland efiort on the-part of the operator, which may 'bequickly and easilyloaded without jamming, and whichis positive in its action withoutreliance upon gravity feed. 7 7

Another object is to provide a durable, compact, lightweight and highlyefiicient nail driving tool of the above class which may be safely usedby an inexperienced operator without danger of injury to himself orothers or to the work. Still other objects of the present. invention areto provide such a tool having a simple highly eflicient guard meansadapted to prevent accidental discharge of a nail from the tool duringoperation and thereby to protect the operator and fellow workers from..the possibility of injury which might otherwise result from uncontrollednails flyingthrough space under the impact of the driving hammer; and toprovide such a tool having a simple protective movement limit: i'ngmeans which permits a nail to be driven the full length thereof by thetool and thereafter.

automatica ly prevents needless or undesirable countersinking of thenail beyond a predetermined extent regardless of the length of the nail.

Other objects are to provide such a nail driving tool which is readilyadaptable for use with nails of various lengths within a given range; toprovide a hand loaded nail driving tool having improved means tofacilitate loading or feed-.

ing of nails to the tool; and to provide such a tool which readilyreceives the nail to be driven and positive y holds the latter inoperative position, permitting use of the tool at any con venient angle.I

Another object of this invention is to provide a tool embodying a naildriving plunger which may be readily adapted for actuation by con-vventional types of hand operated power hammers,v

as for example pneumatic hammers of the type commonly employed forriveting operations.

, Other objects of 'thisyinvention will anpearin the. followingdescription and; appended. claims; reference bei'ng" had to the'eeconfniiairiyingdraw 7 Claims. (01.1-46.1)

ings forming a part of this specification wherein like referencecharactersdesignate corresponding parts in the several views. I

The; above and otherobjects are accomplished in a preferred embodimentof the'present in vention comprising a vibratory nail driving memberpreferably adaptedfor power actuation by a? power driven: pneumatichammer or other ham; mer means suitably powered for exampleby el'ec-'tric or hydraulic'meansewhereby arapid vibratory nail Crivingmotion ofsmallamplitude is im parted to the nail driving member. -A-nailholdingheadhaving a longitudinal nail receiving chafnbe'r therein is slidablymounted on the vibratory nail driving member in such a manner that thelatter may be moved forward into the chamber to displace a" nailtherein; whereby the nail is forceably driven from the hea'd throughafora Td OpeninQ of the hamber. 4 H Manual loading of a nailsubstantially lengthwise into the nailreceivi'ng chamber is permitted Bya naiij receiving" slot within the side'w'allof the" head and o eninglongitudinally into; the

chamber A fee troug extending longitudi nally withinthe upper surface ofthe nail holdhead" converges to tl'i "ail" receiving slot to faci itateloading of a na l thereinto. Thus a nailplaced withirilthe' span of thetrough is readily guided along the converging sidewalls thereof to henail rec "vi ngj slot and into the aforementioned chamber.

mentioned feed trough at the rearwardextremity thereof. togreceive theenlarged head of the nail.

and guide the latter to a desiredioperative position within" the nailreceiving chamber. In order to permit positivemanual control over .thenail during the loadingooperation central por- .of theopposingflsidewalls oflthefe'ed trough are deepened to: provide rounded fingerreceivingngrooves haying, the lower portions thereof opening immediatelyabove the nail receiving chamhern; o'llhushthe operator, while holding anail. between-hisflthumb. andforefinger for example, -may vplacethe-riailwith-in-the confines of the feed trough with the nail headwithin. the deepened. lnailnheadt receiving portion thereof.

The operator v may thenfollow the vnail downward withhis fingersalong-the converging; sides of 'sh ndrcs ti e y force the. nail i t J 'ii h m er'e zfine fin e t e onith 1 "upper portion-of the-nail.

Per lol eiii Q fii eii' nli a 1b: a o o ham s with .res e ttq e v ra memifec l t tedj r ee ender or n i head i ece v n tr u h olo eie tiaihe ide.Oi.,. he a ore,

Suitable nail retaining means are provided within the nail receivingchamber for yieldingly and frictionally engaging the nail so as to holdthe same positively in central alignment in an operative position withinthe chamber. Accidental displacement of the nail within the chamber orits accidental dropping through the discharge opening of the chamber isthus prevented regardless of the angle at which the tool may be held.

Details of a preferred construction of a nail driving tool embodying thepresent invention are illustrated by way of example in the followingdrawings wherein:

Fig. 1 is a fragmentary view partially in longitudinal mid-section andpartially in elevation, showing the nail driving tool in operativeposition for driving a nail into a workpiece.

Fig. 2 is a fragmentary enlarged plan view the tool and workpiece ofFig. 1, showing the tool in the operative position upon completion of anail driving operation.

Fig. 3 is a transverse section taken in the direction of the arrowssubstantially along the line 3-4 of Fig. 2.

Fig. 4 is a transverse section taken in the direction of the arrowssubstantially along the line 4-4 of Fig. 2.

Fig. 5 is a transverse section taken in the direction of the arrowssubstantially along the line 5 5 of Fig. 2.

Fig'. 6 is a transverse section t ken in'the direction of the arrowssubstantially along the line 66ofFig.2.

Fig.'7'is a longitudinal section taken in the direction of the arrowssubstantially along the line 1-1 of Fig. 4.

Before explaining the present invention in detail it is to be understoodthat the invention is not limited in its application to the details ofconstruction and arrangement of arts illustrated in the accompanyingdrawings, since the invention is capable of ot er embodiments and ofbeing practiced or carried out in various ways. Also it is to beunderstood that the phraseology or terminology employed herein is forthe purpose of description and not of limitation.

The present invention is descri ed by way of example in connection witha nail driving tool which is readily adaptable. for-use with aconventional type of pneumatic hammer, indicated by the numeral 10,Figs. land 2. In this instance the tool comprises a generallycylindrical nail holding head, indicated by the numeral.l2,. slid-1 ablymounted on a vibratory nail driving s aft !4 for movement longitudinallythereof. In Fig. l a nail. I6 is shownheld by the head I2 in.an.operativeposition preparatory to ,be driven into a workpiecel8. 1 a

Although a preferred application of thepresent invention is illustratedherein in connection with a pneumatic type of hand .operatedpoweractuatedghammer, it is to, be understood that the tude to the hammermember 24. The hammer in is manually supported by a handle 26 and isprovided with connection and trigger means, not shown, whereby airpressure may be suitably supplied through flexible conduits and.controlled for selective actuation of the vibratory hammer 24. Theforward end of the housing 20 is reduced in diameter to a projectingnose 2! and is provided with a cylindrical shaft holding bore 28 adaptedto receive and support the butt portion 39 of the vibratory shaft I4,which is of suitable diameter to effect a snug sliding fit within thebore 28. Integral with the shaft I 4 at the forward end of the butt 30is an annular movement limiting flange 32 suitably located with respectto the dimensions of the hammer I!) so as to abut the nose 2'! thereofwhen the butt 3B is inserted into the bore 28 in abutting relation withthe face of the hammer 24.

In the present instance, the forward body portion of the housing 20 isexteriorly screw threaded at 34 to receive a comparatively heavy coilspring 35 dimensioned to be screwed tightly on the threaded portion 34.The forward coils of the spring 35 are of successively decreasingdiameter and converge around the reduced nose 2! and flange 32, Fig. l,with at least one coil 35a wrapping around the shaft l4 forward of theflange 32 in a manner for resiliently urging the latter i hammer ID.

The head !2 may be constructed of any suitable material, preferably alightweight aluminum or magnesium alloy, and is formed with a generallycentral bore or nail receiving chamber 35 extending longitudinallytherethrough in diameter for conveniently receiving the largest nailhead for which the tool is adapted. A rearward extension 38 of the headl2 of reduced exterior diameter is provided with a continuation oft'nebore or chamber 35 and is adapted to receive the forward end of theshaft [4 on which the head I2 is firmly and securely supported. In thisconnection, the diameter of the shaft 54 is selected to permit a snugfreely sliding fit within the cham-,

'; ber 36.

present invention is not dependent upon such 5 The limit of relativesliding movement between thehead l2 and shaft [4 is determined by paireddiametrically opposed guide slots 40 extending longitudinally of theshaft I4, Figs. 1 and 6, with-' in which ride a pair. of movementlimiting guide lugs 42 projecting into the bore or chamber 38 frompaired essentially semi-annularretaining plates 44 suitably secured. tothe extremity of the extension 38 by a plurality of Allen-type screws46,. 'Iihe outerperipheries of the retaining plates 44 conformsubstantially to the re duced diameter of the extension 38, whereastheir inner peripheries preferably conform to the diameter of thechamber 35 to comprise substantially a rearward continuation thereof.

In assembly of the tool the forward'end of the shaft i4 is insertedintothe bore 35 of the extension'38 until'the forward extremities "ofthe paired grooves lil pass the assembled posi tions of the lugs 4'2.Thereafter the retaining plates 44 are assembled with their projectinglugs 42 within the grooves 48 and are secured to the extension 38 by thescrews 45 to limit the forward movement of the' he ad 12 relative tdtheshaft 14 and thereby .to prey ent' accidental "sep aration of thesemembersv fin o'perationi of a sesses 5 too]? It "isalso"to-beobserved-that the 'engage-F ment between the lugs 42' antlgroovles 4'0 prevents: relative rotation between the shaft Ml and headl2. Thus thelatter is readily held 'in 'ian up rightoperative"positionduring? operation: of the; toolas described hereinafter. q The body ofthe head I2 for'wardof the extension 38" is preferably of suffieientdiameterand length to: accommodate two longitudinally 'spaced'sets ofspring pressed nail retaining and centering-"balls 18; Figs; 1 and 3'.Each set com-r prises three balls-48 spaced circumierentially aroundthechambe'r 36,-: whereby the six balls 48 efigagea nail"withiri the"chamber 36 at three substantially equi-angularly spaced points at.e'a'jch of two locations spaced 1on'gitudinall-y of Accordingly-'theballs 48 are disposed aianced forces on the nail{ for frio-' liyliolding'the' sameposinveiy' against acnuentar displacement an diincentral: longitudinal align-merit: within the chamber 35 regardlesstheangle at which the tool or head {2 may-be held The balls lfi'of eachset are contained Withih thre'e Suitab1y-spaced radial Wei-1S 50'Communicaung -betv'veen the chamber 35 and the ex-' te'rior ofithe head62 The outer'opening of each-well Eli-is adapted toreceive its retainingcan 4'8 andi's preferahlysrew threaded at 52 to receive a-retainings'c'rew-or plug 54. The base ofeaoh weir 50 is provided with an inneropening of' manerdiameter than the ball communi' c'ati'rigwitli-the'cham-ber- 36 and comprises an aiinular seat 56 forthe ball Q8;whereby-the latter is retained within its well 50 but-permitted tdpijectpartially-into "the-chamber 35. Each ban 4's is resiliently urged intoits seat'ed'positibn projected into the chamber 36 by'a"coi1 spring 58under compression between the'screw 54 and ball 58.

As indicated in 'Fig; 3, the eq'ui-angular spacing of-"the balls 48 isnot critical to the efficientop erati'on of the present invention -and-may' be suitably varied to meet particular construction requirements ofthe tool. In" such situations as in-the'present instance, thetensions'in-the spring 58 are" ad-justed with" respect to thecircumferentia-l locations-of the ba1ls4'3 so that the forces exertedthereby on a centrally aligned nail will bsubstantially ba-lancediPreferably; the two-upper balls reef each set are disposed to projectinto the chamber 3 6 at equal lateral angles of attack from oppositesides and somewhat above the longitudinal center line thereof,-- Fig;3', so as to exert equal" down-ward forces on opposite sides of a" nailWithin the chamber 352 The lower ball- 48" of each set'is disposed toproject into the chamber 3% from below the'm'id-line thereof to equalizethe'verti'oal forces exertedon the nail bylthe' twoupper balls 48. Thetwo upper balls 48 are also preferably disposed so as to meet thecylindrical sides of a nail within thecham-ber 33 at points above thecenter line of the nail: Thus immediately upon passage of a nail belowthe slot 6% and into the chamber 36, the nail will besnapped into theaforesaid central longitudinal alignment by theaction of the springpressed-balls 481 I I Loading-or feeding of-a-nail l-6 into'the chamber-36 is-= readily [permitted through a nail, receiving slot 6 Figs. 1through which 1 extends longitudinally of the chamber 36 and opens tothe exterior of the head I2 through the upper sidewall thereof. The slot60 terminates rearwardly at email-head receiving enlargement 62, of substant-ial-ly'thediameterofthe' chamber '36-, Figs,-

of the shaft I4. Thus when a nail I16 is inserted into: the chamber 36in the manner described hereinafter, with its head 64 passing throughthe slot: portion 62, the nail It: will 'lie' within the chamber 36substantially asshown in Fig: 1'.:

In this'po'sition the shaft M will be at the rear ward limit of movementrelative to the head-I2 permitted by the studs 42 withinthe-g'rooves'flflx The nail head 64'wi11 thus be adjacent: the shaftextremity 66 in position to be driven forward through the chamber 36upon forward relative movement of the shaft M: By virtue of the con:--caveextremity of the; shaft I4, the head 64 Will be continually'centeredwithin the chamber--36 during a nail' driving operation. Thus thedangerous tendency to cook a'nail out of longi=-- tudinal alignmentwithin the chamber 36, where by the nail may be accidentally shotthrough the slots 60, 82 by the impact of a nail driving. operation, isminimized. This safeguard is especially important with the use of socalled headless or finishing nails which would other; wise beparticularly subject to accidentaldis charge'from the slots 6i], 62 inoperation of the tool.

The nail receiving slot 69 extends forward from the slot 62sufficientl-y to'permit substan: tially lengthwise passage into thechamber 36, of a nail of'average length-which; the tool is intended tohandle The forward end of the slot 69 terminates at a forward annularguard portion 68 of the head 12' comprising an annular sidewallenclosure'for the forward end:- of the chamber 36. The forward' tip-ornose I!) of the guard 68 is flattened'or blunted to permit pressureagainst a workpiece is without the danger of damaging the latter bybeing embedded therein under the impact of a nail driving operation. As"will be apparent hereinafter, the annular guard portion 68 serves as aneflicient safety measure to prevent the accidental discharge of a nailthrough the slot 60 'during the initial impact of'a hammering or naildriving operation, particularly before the point of thenailis secure 1yembedded within the work I8. h r

An important-feature of the present invention is the means wherebyrapid" manual loading of the'chamber 36 with a-nail-tobe driven isreadily accomplished. To" this end the upper portion of the'head I2 isprovided with a longitudinally extending groove or trough 12 of V-shapedcrosssection which converges at its base to the nail receiving slot 69.Thenail may be placed by the operator anywhere on the upper portionfofthe head IZ within the span ofthe trough- 12 and substantiallylongitudinally thereof. trough 12 will then guide the nail into the slot60 Without undue effort or skill on the part of the operator. A slightlydeeper nail head receivingportion 14 of the trough 12 is provided at therearward extremity of the latter, Figs. and. 5', directly overtheenlarged nailhead receiving opening 62. U V

Asindicated in Fig. 5, the depth-of the trough portion M with respectatothe trough is selected to accommodate nailheads of the largest diameterwhich may be'conveniently retained Within the chamber; 36. Accordinglywhen a nail is placed with its body within the trough i2 and ,itsenlarged 'head,within the trough 14;, the nail is readily-guided towardthenail' receiving --sl0 ts- 60; 62 by the converging walls of therespective troughs I2, 14.

In order to simplify further the loading of the chamber 36 and to permitpositive control of the nail by the operator during the loading operation, rounded central finger grooves IS are provided within the opposedsidewalls of the trough 12. In the present instance the grooves 16 areformed by a substantially spherical cut into the upper surface of thehead I2 and sidewalls of the trough I2, Figs 1, 2, 4 and 7, with thelowest points of the spherical cut meeting the base of the sidewalls ofthe slot 63 at the opening of the latter into the chamber 36, Fig. 4.Accordingly as a nail held within the fingers of the operator is fedinto the chamber 35, the fingers are readily guided by the roundedfinger grooves is directly to the upper opening of the chamber 35 at thelowermost region of the paired converging grooves 76. by finger pressurebelow the level of the base of the slot 63 whereat the two upper ballstil of each set will engage the cylindrical sides of the nail above thecenter line thereof and exert a downward force thereon to force the nailinto the centered operative position within the charm ber 36.

In operation of the tool, the assembled head I2 and shaft I4 areconnected with the hammer I as shown in Fig. 1. inserted into theretaining bore 28 therefor in abutting engagement with the vibratorypower operated hammer member 24 and with the movement limiting flange 32seated firmly against the nose 2?; whereat it is resiliently held in theseated position by the coil spring 35, 35a screwed on the threadedhousing portion 34. The head I2 is then slid forward along the shaft I4to the nail loading position at the forward limit of movement permittedby the studs 42 riding within the slots 49, Fig. 1. At this position,the concave centering extremity 66 of the shaft I4 will lie immediatelyto the rear of the nail head receiving slot 62.

While holding a nail between his fingers, as for example between histhumb and index finger, the operator then readily places the nail withinthe span of the V-troughs I2, I4 with the body of the nail within thetrough l2 and the head of the nail within the trough I4, and slides thenailby a guided downward movement along the converging sides of thetroughs 12, I4 to the upper openings of the slots 60, 62. Insubstantially the same motion, while the head of the nail is confined bythe sidewalls of the nail head holding trough I4, the operator slideshis fingers along the length of the nail without releasing his grip'thereon to the paired rounded finger grooves I6 which guide the fingersto a point at the lowermost portion of the grooves I6 immediately abovethe lower opening of the slot Bil into the chamber 36. The nail isaccordingly moved downward through the slots 60, 62 to a position ofalignment for reception by the chamber 36. Upon continued pressure onthe nail from above by the thumb or forefinger, the nail is readilyforced below the slots 69, 62 whereat the sides of the nail are engagedby the paired sets of spring pressed upper balls 48 and snapped intocentral position within the chamber 36, I

' If a nail such as the nail I6 is employed which is longer than thelength of the slots 60, 62, the nail is preferably inserted angularlydownward into the slot 60 with the nail point foremost until'the latterprojectsthrough the annular guard The nail may then be forced The shaftbutt 3?} is 6 erator then actuates the hammer III in accordance withconventional practice to effect a power driven high frequency vibratorymotion of small amplitude to the hammer member 24. The repeated impactsof the vibratory hammer member 24 are imparted to the head of the nailthrough, the vibratory shaft I4, driving the nail intothe work l8. Inthis connection, the rounded concave forward extremity 66 of the shaftserves to center the nail head and is particularly useful where headlessor small headed finishing nails are employed. Thus the nail is drivenlongitudinally of the shaft I4 directly into the work I8. The danger ofimparting a glancing or an-,

gula impact to the nail head which might causethe nail to fly from thehead I2 through the slot 60 is minimized. Likewise, particularly in thesituation where the length of the nail is shorter than the length of theslot 60, the annular nose guard 68 around the forward extremity of thechamber 36 retains the nail against accidental discharge through theslot 60, particularly during the initial stages of the nail drivingoperation before the point of the nail is secured within the work I8. 1

As the nail is driven into the work I8, the vibratory shaft I4 graduallymoves forward withinthe chamber 36, driving the nail through the annularnose 68 or discharge end of the chamber-36 until the guide lugs 42riding within the slots 40 engage the shaft I4 at the rearward extremityof the slots 40 and prevent further relative forward movement of theshaft I4 with respect to the head I2.

The length of the slots 40 is preferably determined so that the forwardextremity 66 of the shaft I4 will just reach or slightly clear theforward discharge end 68 of the chamber 36 at the same time the lugs 42reach the ends of the slots 40, Fig. 2. The nail will be driven its fulllength into the work IB, whereupon continued forward movement of theshaft I4 is stopped and injury to the work I8 by undesirablecountersinking is avoided regardless whether the vibratory driving poweris immediately discontinued or not. Likewise injury to the work I8 bythe head I2 is also avoided by the blunted nose ID of the latter whichpreferably provides sufiicient area to abut the work I8 without beingdriven into the same by the ordinary vibratoryimpacts of the ham mermember 24.

Obviously, the length of the slots 40 may be predetermined to limit thecountersinking of the nail to any desired extent or to prevent anyappreciable countersinking. By removing the re-' taining plates 44 fromthe head I2 and the coil spring from the hammer I0, the shaft I4 may bereadily removed and replaced by a similar shaftJMi having guide grooves40 of a-'different length where'it is desired to change the'extent ofcountersinking permitted by the tool.'

I claim:

1. In a nail driving tool, a nail holding head having a longitudinalnail receiving chamber therein, said head having a longitudinalna'ilfeed ing slot in the sidewall thereof communication with saidchamber to permit substantially lengthwise passage of a nail into saidchamber and also having a nail discharge opening in an end thereof, avibratory nail driving member movable within said chamber to drive anail therein through said discharge opening, and means to facilitatemanual feeding of a nail substantially lengthwise into said chamberthrough said nail feeding slot and including a trough in the sidewall ofsaid head extending longitudinally of said chamber and converging tosaid nail feeding slot.

2. In a nail driving tool, a nail holding head having a longitudinalnail receiving chamber therein, said head having a longitudinal nailfeeding slot in the sidewall thereof in communication with said chamberto permit substantially lengthwise passage of a nail into said chamberand also having a nail discharge opening in an end thereof, a vibratorynail driving member movable within said chamber to drive a nail thereinthrough said discharge opening, means to facilitate manual feeding of anail substantially lengthwise into said chamber through said nailfeeding slot and including a trough in the sidewall of said headextending longitudinally of said chamber and converging to said nailfeeding slot, and means to facilitate manual insertion of a nail throughsaid nail feeding slot and including finger recesses in opposedsidewalls of said trough.

3. In a nail driving tool, a nail holding head having a longitudinalnail receiving chamber therein, said head having a longitudinal nailfeeding slot in the sidewall thereof in communication with said chamberto permit substantially lengthwise passage of a nail into said chamberand also having a nail discharge opening in an end thereof, a vibratorynail driving member movable within said chamber to drive a nail thereinthrough said discharge opening, means to facilitate manual feeding of anail substantially lengthwise into said chamber through said nailfeeding slot and including a trough in the sidewall of said headextending longitudinally of said chamber and converging to said nailfeeding slot, and means to guide a nail into operative driving positionwithin said chamber with the head of the nail adjacent said drivingmember and including a transverse nail-head guide slot in the sidewallof said trough and leading to said feeding slot.

4. In a nail driving tool, a nail holding head having a longitudinalnail receiving chamber therein, said head having a longitudinal nailfeeding slot in the sidewall thereof in communication with said chamberto permit substantially lengthwise passage of a nail into said chamberand also having a nail discharge opening in an end thereof, a vibratorynail driving member movable within said chamber to drive a nail thereinthrough said discharge opening, means to facilitate manual feeding of anail substantially lengthwise into said chamber through said nailfeeding slot and including a trough in the sidewall of said headextending longitudinally of said chamber and converging to said nailfeeding slot, means to facilitate manual insertion of a nail throughsaid nail feeding slot and including finger recesses in opposedsidewalls of said trough, and means to guide a nail into operativedriving position within said chamber with the head of the nail adjacentsaid driving member and including a transverse nail-head guide slot inthe sidewall of said trough and leading to said feeding slot.

5. In a nail driving tool, a nail hOlding head having a nail receivingchamber therein communicating with a discharge opening, said head alsohaving a nail feed trough communicating inwardly with said chamber anddiverging outwardly to facilitate feeding a nail into said. chamher, anda nail driving member movable within said chamber to drive a nailtherefrom through said discharge opening.

6. In a nail driving tool, a nail holding head having a nail receivingchamber therein communicating with a discharge opening, said head alsohaving a nail feed trough communicating inwardly with said chamber anddiverging outwardl to guide a nail into said chamber, said trough havingfinger recesses in opposed sidewalls thereof to facilitate manualinsertion of a nail thereinto, and a nail driving member movable withinsaid chamber to drive the nail therefrom through said discharge opening.

7. In a nail driving tool, a nail holding head having a nail receivingchamber therein communicating with a discharge opening, said head alsohaving a nail feed trough communicating inwardly with said chamber anddiverging outwardly to guide a nail into said chamber, said troughhaving a nail-head guide slot in the sidewall thereof leading to saidchamber for guiding the head of the nail to a predetermined positionwithin the chamber, and a nail driving member movable within saidchamber to drive the nail therefrom through said discharge opening.

PATRICK H. BRENNAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,539,473 Ellwood May 26, 19251,604,675 Bernard Oct. 26, 1926 2,009,580 Govanus July 30, 19352,078,012 Newell Apr. 20, 1937

